There are many reasons why people decide to install a home drinking water purification system. Their water might taste odd, have a strange color or smell, or perhaps their water is what is called “hard water” (water that has high mineral content) which often causes problems with laundry.  Mostly water purifiers are installed at residences that have their own wells, if you’re connected to the city water line, the water usually has already been treated in a water treatment plant and if there’s something wrong with it, you should contact the water company or state department of health. Rusty pipes can also be the reason for your bad water and should be replaced instead of adding a water filter.

A good first step would be to get your water tested to find out what kind of purifier is required, because different kinds of purifiers remove different types of bacteria and minerals. You can take a water sample to a laboratory, either a private one or your county / state department of health. This is something you should always do regularly if you have your own well.

An activated carbon water filter

An activated carbon filter can remove many organic chemicals and pesticides, hydrogen sulfide, mercury and radon gas and is good for reducing taste, odor and color problems in water. Activated carbon filters usually have replaceable activated carbon cartridges and always require regular maintenance or bacteria will start to breed in the filter.

A reverse osmosis water filter system

Reverse osmosis systems, while being more expensive, can in addition remove calcium, magnesium, phosphorus, nitrate, boron, potassium, sulfate, radium and salts.

Oxidizing greensand or zeolite filters require that you regularly regenerate the system by adding potassium which is dangerous if it gets into your eyes and gloves are required to protect your skin.

An ion exchange water filter

Ion exchange water filters work by running the water through small resin beads. It can remove barium and small amounts of iron and manganese . The resulting water includes added sodium, which might not be good for you if you have blood pressure issues or hypertension.

Chlorinating the water is also an option, but I’d advice against that, because if the system isn’t working properly, the water might in fact become poisonous. Likewise, killing bacteria using a UV filter is not very good either because there’s no way to know (without constantly testing the water) if the system is actually working.

Ozone water treatment is another quite expensive solution. When compared to chlorination, it’s better at killing bacteria and viruses. Ozone is formed by using electricity like in lightning strikes. The ozone gas is then forced through the water, oxidizing iron, manganese, sulfur and some other particles. These particles will then be removed by using a secondary filter. There are still some suspicions that byproducts from the ozonation process might cause cancer.

BioShaft is a green innovative wastewater treatment technology based on Bio-Filtration utilizing biomass carriers. These plants are made using the BioShaft Turbo Reactor that is at the heart of the wastewater technology. The plants have many benefits over traditional wastewater treatment, including the virtual elimination of sludge and odors and requires significantly less land. It is patented in the UK and the patent is pending in the United States. To date there are more than 30 waste water treatment plants throughout the world using this technology.

“The unique BioShaft fixed film process virtually eliminates sludge. Bioshaft is a biological treatment process that uses thousands of special carriers designed to create a large surface area for biofilm growth. This enhances the wastewater treatment process while reducing the footprint of the plant. By collecting and reintroducing this biofilm in to the process again, it allows us to virtually eliminate sludge!”

[Press release]

At least one public waterway in Monteagle was polluted Sunday when a primary treatment basin failed at the city’s waste-water treatment plant.

Almost a 100-thousand gallons of effluent went into Juanita Creek.

Monteagle has two wastewater treatment plants…and this was plant number consisting of an above-ground steel tank.

Monteagle has also begun chlorinating the bypass into Juanita Creek.

[Full article]

(Effluent usually means water pollution, like the output from a wastewater treatment plant or discharge from factories or other industrial sources. Effluent sump pumps, pump waste from toilets installed under the level of local sewer. When talking about waste water treatment plants, treated effluent is often referred to as “secondary effluent”. This semi-treated water is often used to to feed biofilters with bacteria. [Wikipedia])

The purification of waste water produces large amounts of organic sludge, which has to be thickened, treated and disposed of. This is one of the most expensive parts of waste water treatment. This sludge is usually a inconvenient product as it will rot in the air, causing odor problems. Anaerobic processes rely on microbiological processes where organic material is degraded and biogas (composed of mainly methane and carbon dioxide) is pro­duced. Anaerobic processes take place in the absence of oxygen and produce much less excess sludge in a more stable (non-rotting) condition.

Conven­tional, aerobic waste water treatment has been exten­sively applied in industrialized countries, but has the reputation of being expensive and requiring specialist supervision. Aerobic waste water treatment is characterized by a high conversion ratio of soluble BOD into biomass, and thus sludge. Sludge is produced in large quantities, it is composed of mostly water, requiring relatively expensive de-watering, and it may contain pollutants, notably patho­gens and heavy metals, that render the use as fertilizer impossible or difficult. The excess sludge from aerobic treatment however, can be easily digested, yielding sufficient amounts of biogas to make the plant energetically autonomous and lowering operational costs.

Anaerobic waste water treatment has been introduced on full scale on various types of in­dustrial waste water for three decades, both in cold and warm climates. Results have been in most cases successful. Anaerobic processes, carried out in specially designed concrete or steel reactors, result in high quality and short retention times which generally equals reduced con­struction costs. An additional advantage of anaerobic treatment is that it produces a well-digested and stable sludge, which will not rot when exposed to air. It has favorable dewatering characteristics when compared to the “fresh” sludge from aerobic plants.

Distribution of safe drinking water is essential for the protection of public health, but the importance of excrement disposal can’t be stressed enough. Diarrhea is responsible for 17% of ALL deaths of children under 5 years of age in the world. Over 85% of all deaths in african refugee camps are related to diarrhea.

Diarrhea diseases are most usually transmitted by feces being in touch with food or water through unwashed hands or when people drink from contaminated water sources. While proper hygiene and clean drinking water reduces diarrhea in many cases, the treatment of fecal waste plays the most important role in keeping the people healthy.

Osmosis is a physical process in which a solvent moves, without need of external energy, across a semi-permeable (allowing fluids or gases to pass or diffuse through) membrane (a thin sheet of natural or synthetic material), separating two solutions of different concentrations as the denser solution stays on the surface while the less dense goes through it. In reverse osmosis the solvent is forced through the membrane by applying pressure. This way even smaller particles such as salt ions can be separated because the use of pressure enables the use of membranes with more dense structure that wouldn’t let water pass through it using regular osmosis.

Nano-filtration is selected when Reverse Osmosis or ultrafiltration are not suitable. For example, nanofiltration can be used for demineralization.

The water treatment systems Cabello was selling were made by Puretech Water Treatment Systems Inc., a company Cabello worked for in 2006. It was found that Puretech gave him the equipment and handled the paperwork to seal the deals with the residents. Puretech was ordered to pay fines.

The water treatment systems have been uninstalled from the people who bought them and their money was returned.

Cabello’s group usually went to residences right after there had been a break in water distribution when water is often colored by rust in the pipes and the people thought there was something wrong with their tap water, so it made sense that a goverment official wanted to make an analysis.

A grand jury said former superintendent Kevin Transue and former plant employee Daniel Rose discharged sludge - sediment and chemicals left over from the purification process - into the source of drinking water for Binghamton and surrounding communities.

No one was harmed in the alleged dumping of sludge, officials said. Robin Baker, state Attorney General Andrew Cuomo’s executive deputy for criminal justice, refused to say how much sludge was dumped into the river. Baker also declined to say what chemicals were in the sludge.

Rose and Transue were accused of discharging sludge between March 24, 2006, and Nov. 3, 2007, the grand jury said. Additionally, Transue was accused of failing in his duty to monitor and report discharges and to comply with state Department of Environmental Conservation reporting requirements.

[Read the article]

Farmers who use sludge as a fertilizer can use it alone or as to supplement commercial fertilizers. It can be obtained at low or even no cost.

Nutritional value of sludge may vary based on factors such as treatment processes or where it originates from. The soil where it is going to be applied should be tested to determine how much nutrients are needed. If sludge containing too much nutrients is applied it’s going damage the environment, because of this, there are certain regulations and restrictions on usage of sludge. The steepness of slope and soil conditions may limit or even prohibit using it as a fertilizer. There are also limits on how much heavy metals such as nickel, zinc, copper, lead and cadmium the sewage sludge may contain for it to be allowed to be used for land fertilization.

EPA recommendations for the use of sewage sludge:

1. Farmers should not accept sludge or apply it to land without a complete waste analysis.
2. The soil pH on sludge application sites should be maintained above 6.5.
3. Sludge should be applied by injecting it directly in the soil or incorporating it into the soil within 24 hours to reduce the potential for odor and loss of nutrients in runoff.
4. For surface application, use only sludge that has been properly digested and stabilized at the treatment plant.
5. Do not apply sludge long before it will be utilized by the crop.
6. Keep accurate records of sludge applications. Sewage sludge containing heavy metals should be monitored to prevent contamination of soil or groundwater.
7. Excessive rates can contribute to leaching, erosion, and runoff losses; therefore, do not apply more than is needed.

The new nanowire paper is also inexpensive to produce because the nanowires of which it is composed can be fabricated in larger quantities than other nanomaterials.

The new material appears to be completely impervious to water. The material can be left in water for months and when you take it out it’s still dry, and if that water contained hydrophobic contaminants, they have been absorbed.

Made of potassium manganese oxide, the nanowires are stable at high temperatures, so oil within a loaded membrane can be removed by heating it above the boiling point of oil. The oil evaporates, and can be condensed back into a liquid. The membrane and oil can then be used again.

This work was primarily funded by the Deshpande Center for Technological Innovation at MIT.

[More at Physorg]